mac80211: add 802.11 encapsulation offloading support

This patch adds a new transmit path for hardware that supports 802.11
encapsulation offloading. In those cases 802.3 frames get passed
directly to the driver allowing the hardware to handle the encapsulation.
Some features such as monitor mode and TKIP would break when encapsulation
offloading is enabled. If any of these get enabled, the code will alwyas
fallback to the normal sw encapsulation data path.

The patch defines a secondary netdev_ops struct that the device gets
assigned if 802.11 encap support is available and enabled. The driver
needs to enable the support on a per vif basis if it finds that all
pre-reqs are meet.

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qti.qualcomm.com>
Signed-off-by: John Crispin <john@phrozen.org>
Link: https://lore.kernel.org/r/20191125100438.16539-1-john@phrozen.org
[reword comments, remove SUPPORTS_80211_ENCAP HW flag, minor cleanups]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 71 insertions, 0 deletions

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index b720feaf9a74..0344b82a34f5 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -1198,6 +1198,77 @@ void ieee80211_tx_rate_update(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL(ieee80211_tx_rate_update);
 
+void ieee80211_tx_status_8023(struct ieee80211_hw *hw,
+			      struct ieee80211_vif *vif,
+			      struct sk_buff *skb)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct sta_info *sta;
+	int retry_count;
+	int rates_idx;
+	bool acked;
+
+	sdata = vif_to_sdata(vif);
+
+	acked = info->flags & IEEE80211_TX_STAT_ACK;
+	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
+
+	rcu_read_lock();
+
+	if (ieee80211_lookup_ra_sta(sdata, skb, &sta))
+		goto counters_update;
+
+	if (IS_ERR(sta))
+		goto counters_update;
+
+	if (!acked)
+		sta->status_stats.retry_failed++;
+
+	if (rates_idx != -1)
+		sta->tx_stats.last_rate = info->status.rates[rates_idx];
+
+	sta->status_stats.retry_count += retry_count;
+
+	if (ieee80211_hw_check(hw, REPORTS_TX_ACK_STATUS)) {
+		if (acked && vif->type == NL80211_IFTYPE_STATION)
+			ieee80211_sta_reset_conn_monitor(sdata);
+
+		sta->status_stats.last_ack = jiffies;
+		if (info->flags & IEEE80211_TX_STAT_ACK) {
+			if (sta->status_stats.lost_packets)
+				sta->status_stats.lost_packets = 0;
+
+			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
+				sta->status_stats.last_tdls_pkt_time = jiffies;
+		} else {
+			ieee80211_lost_packet(sta, info);
+		}
+	}
+
+counters_update:
+	rcu_read_unlock();
+	ieee80211_led_tx(local);
+
+	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
+	    !(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED))
+		goto skip_stats_update;
+
+	I802_DEBUG_INC(local->dot11TransmittedFrameCount);
+	if (is_multicast_ether_addr(skb->data))
+		I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
+	if (retry_count > 0)
+		I802_DEBUG_INC(local->dot11RetryCount);
+	if (retry_count > 1)
+		I802_DEBUG_INC(local->dot11MultipleRetryCount);
+
+skip_stats_update:
+	ieee80211_report_used_skb(local, skb, false);
+	dev_kfree_skb(skb);
+}
+EXPORT_SYMBOL(ieee80211_tx_status_8023);
+
 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
 {
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);